Formation of brushes



H. CAVE FORMATION OF BRUSHES May 21, 1946.

: Filed March 1:5, 194s pennant; 21, 1946,

FORMATIONOF BRUSHES Henry Gave, Hartford, Conn; asslgnor to The Fuller Brush Company, Hartford, Conn., a corporation of Connecticut Application March 1a, 1943, Serial No. 479,990 2 Claims. o]. soc-21) This invention embodies the idea of making a brush strip comprising a trough-shaped piece of metal or other suitable material stifi enough to rigidly hold bristles of any desired character the bends of which are firmly secured and held within the base with the ends or rest of the bristles projecting from the mouth of the strip and which strips of this character may be formed into various shapes depending upon the sort of work to which the brush is to be subjected, .that is, for household use or other uses.

An object of the invention, among others, is the production of brushes of this type in a particularly expeditious and economical manner and at the same time brushes which possess all of the essentials as to weight, strength, and effectiveness in operation that are required in such brushes.

A brush strip and a process for making it and embodying the invention and in the practice of which the objects herein set out, as well as others, may be attained is illustrated in the accompanying drawing, in which:

Figure 1 is a diagrammatic view illustrating the manner of making the improved brush strip embodying my invention.

Figure 2 is a view in partial section on a plane denoted by the broken line 2-4 of Fig. 1 on enlarged scale.

Figure 3 is a, view in. section on a plane denoted by the broken line 3-3 of Fig. l on enlarged scale.

. Figure 4 is a view in section on a plane denoted by the broken line t---& of Fig. 1 on enlarged scale.

It has been common practice heretofore to form brush s'trips comprising grooved structures with bristles doubled and crowded into the groove with the major portion of the length of the bristles projecting from the mouth of the groove to comprise the brush element of the structure, and the term bristles is employed herein to denote any of the various kinds of material, whether of synthetic, animal, vegetable, or'metallic character, commonly employed in the mak ing of brushes. These strips are employed in various ways in the formation of brushes of various types both for household, commercial, and other purposes. a core wire having been commonly inserted within the folds of the bristles and these together with the pinching a material of a flowing or mobilecharacter which is employed as an aid in securing,the bristles within the trough-shaped strips, this material be ing of a thermo-plastic or thermo-setting nature whereby upon the application of a proper degree of heat it may become plastic or may harden or set. As particularly illustrated herein this material of a thermo-plastic nature is used in powdered form which is introduced into the trough of the strip before the bristles are inserted and upon the insertion of the bristles and the application of force to press the sides of the grooved strip together to secure the bristles the powdered material will be caused to flufi up and flow into and penetrate the interstices between the britsles and thereafter, upon the application of heat in any desired manner, will become plastic, enveloping and burying the bristle roots within the strip in said plastic mass which, upon hardening, will tightly secure the bristles in place.

Any desired means for introducing the thermoplastic material into the base strip and thereafter treating it as above described may be employed, one such means being illustrated in the drawing herein comprising a diagrammatic view and including a table 5 supported upon legs 6 and having at one end a roller support I mounting two pairs of rollers 8-9 for operating upon a flat strip ll] of metal or other suitable material for forming the base of the brush. The rollers 8 impart a partial grooved form to the strip and the rollers 9 increase this grooved form, from the latter rollers the strip passing between supporting rollers II. V

A receptacle l2 supported in'an elevated position above the strip has a spout 13 with a fiattened end It entered into the groove in the now' partially grooved portion l5 of the strip.

bottom extends into the partially grooved portion action of the sides of the trough-shaped strips 1 which are compressed tightly against the sidesof I5 of the base strip and doubles the fibers into said groove, the sides of the base strip now immediately encountering. a pair of presser rolls 22 by the operation of which the sides of the In this operation of pressing the fibers down into the grooveby the wheel I8 and the action of pressing the sides of the bristles together by the rolls 22 the powdered thermoplastic material is completely distributed throughout the interstices between the fibers or bristles and the latter within the grooved strip are thoroughly embedded in this powdered material.

The description thus far has specifically set forth the use of a thermo-plastic material. Use of a thermo-setting material will follow substantially the sam treatment, being initially of a flowing character it may be caused to enter the trough in the brush strip as describedwith respect to the thermo-plastic material of a powdered flowing character. The strip containing either the thermo-plastic or therma -setting ma terial now being subjected to a proper treatment to cause the material to soften or to set, as the case may be, the bristle as to the roots will be completely embedded in the material within the grooved base, and such material now being al-- lowed or caused to harden either by the application of heat or upon cooling, the bristles will be firmly embedded and secured within the base.

Any heat from any source may be employed but I have shown herein a source of electric energy for accomplishing} this purpose, these comprising electrodes 26-25 supplied with elec materials shall be of any particular nature asany of such adhesives possessing the necessary characteristics will suffice. As an example, shellac, Bakelite, or similar thermo-changing materials in mobile form may be utilized as such material. When the strip 23 of material con-' taining the bristles with their roots thoroughly embedded in the thermo-changing material in a mobile form becomes subject to the action of heat, it of a thermo-plastic nature, it is caused to adhere tenaciously to the fibers and upon passing from th heated zone the material solidifies. If of a thermo-setting nature solidification takes plac on cooling and in both cases the bristles are firmly secured in place and form a strip 28 which may be by a continuous operation extended to'such length as may be desired to be subsequently utilized as may be thought expedient in the formation of brushes of various kinds.

While a wire 20 has been shown in the drawing herein as engaged within the. loops of the fibers I do not contemplate the necessity of such use in all instances as there will be cases in which this wire may be well dispensed with and the adhesive and the squeezing action of the sides of the bristles in place.

2' invention contemplates the securing of bristles or brush material within openings in brush bases or backs, and particularly in grooved base strips and by the use of any of the well known thermo-plastic or thermo-setting materials that will hardenor become set under heating and cooling treatment, both thermo-plastic and thermo-setting materials, although utilizing heat at some time during the change from one condition to another, finally retaining their set condition under cooling action, the thermoplastic after the application of heat to soften it and the thermo-setting retaining said condi= ion after having attained such set condition upon the application of heat.

I claim:

1. A method of preparing a strip of brush material which consists in forming a channel in a moving length of suitable material, inserting a powdery theme-changeabl plastic adhesive into the moving empty base of the channel, inserting bristle-like element in orderly array between the sid legs of the moving channel and into contact with the adhesive, to cause the latter to fluff up and at some time during the forming of the brush strip, closing the legs of the channel on the bristle-like elements so that considerable pressure is applied thereto and also to the adhesive, thereby squeezing the latter and dispersing it throughout the bristl roots, applying a localized heat directly to successive portions of the assembled strip to change its formative character and then permitting cooling to cause gripping action of the thermo-plastic material upon the bristles.

2. A method of preparing a strip of brush material which consist in forming a channel in a moving length of suitable material, inserting a thermo-plastic adhesive in powdered form into the moving base of the empty channel, inserting bristle-like elements in orderly array between the side legs of the channel while the latter is moving and into the adhesive powder, causing the latter to flufi up and penetrate between the bristles, closing the legs of the channel on the bristle-like elements so that considerable pressure is applied thereto and to the powdered adhesive, thereby squeezing the latter and further dispersing it throughout the bristle roots, then applying a localized heat directly to the successive portions of the assembled strip to soften or fuse the adhesive so that the pressure within and by the channel will cause the plastic to further flow into the interstices between the bristlelike elements and thereby grip the interposed bristles, and then finally permitting cooling to cause gripping action of the thermo-plastic material upon the bristles.

HENRY CAVE. 

